Update workflows to use actions/checkout@v4

Since Node 16 has been deprecated, Github is requiring all Actions users
to migrate to Node 20, and therefore use actions/checkout@v4. This also
applies to other jobs that use Node 16 as their runtime.

See: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install dependencies (Ubuntu)
       run: ./.github/scripts/install-dependencies-ubuntu.sh

.github/workflows/codeql-analysis.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         # We must fetch at least the immediate parents so that if this is
         # a pull request then we can checkout the head.

.github/workflows/doxygen.yml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install dependencies
       run: ./.github/scripts/install-dependencies-ubuntu.sh
@@ -24,7 +24,7 @@ jobs:
       run: find ./build -type f -print
 
     - name: Deploy generated documentation to Github pages
-      uses: peaceiris/actions-gh-pages@v3
+      uses: peaceiris/actions-gh-pages@v4
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_dir: ./build/docs/html

.github/workflows/kernel.yml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install kernel dependencies
       run: ./.github/scripts/install-kernel-dependencies.sh

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install dependencies
         run: ./.github/scripts/install-dependencies-ubuntu.sh